Stable and active monolithic palladium catalyst for catalytic oxidation of methane using nanozeolite silicalite-1 coating on cordierite

Abstract

An active, stable, and efficient monolithic catalyst for low temperature catalytic oxidation of methane is of great importance in various combustion applications. Mesoporous silicalite-1 zeolite coatings on cordierite monoliths are prepared by a sucrose-modified steam-assisted crystallization (SAC) method. Addition of 4 mol% of sucrose to the SAC system reduces the silicalite-1 crystal size from 2–8μm to 200–250nm. Further addition of sucrose degrades the zeolite crystallinity, and reduces the surface area and micropore volume. The nanozeolite coating possesses good mechanical stability with a weight loss of 0.5wt%. The Pd catalyst supported on the silicate-1 coated monolith exhibits excellent stability and catalytic methane oxidation activity. CH4 conversion was >99.4% after 72h time-on-stream at 450°C. The T50 and T90 for 1% CH4 were 286°C and 347°C, respectively, and complete conversion of CH4 was achieved at about 400°C.